Atari ST Emulation with MIDI & VGA

Teensy forum member Jean-Marc, who you may recall from his Teensy 4.0 Atari 520ST Emulator, is back with some exciting updates on the project.

For starters, as fun as it is to output the display to a tiny 320×240 TFT screen, some tasks are more practical on a “real” monitor — which is now possible thanks to the addition of VGA output.

In addition to its groundbreaking GEM-based GUI, the ST excelled in audio, with Cubase and Logic Pro both originating on the platform. Two standard 5-pin DIN MIDI ports allowed the computer to talk to other instruments as well, and thanks to Teensy’s USB MIDI support, sequencers running in the emulator can also output to real MIDI devices (with the appropriate dongles).

Complete project details and updates can be found on GitHub. Note that a Teensy 4.1 with PSRAM added is required for full 640×400 display resolution.




Portable Data Acquisition System

Teensy boards power all manner of commercial products, being an ideal solution for high-speed data acquisition, and we were particularly excited by this system from Bolder Flight Systems.

BFS CEO Brian Taylor shared this Teensy 3.6-based unit, which was developed in conjunction with the International Test Pilots School (ITPS) to facilitate test pilot and flight test engineer training on fixed or rotary-wing aircraft.The system logs inertial navigation data, airspeed, altitude, temperature, and 12 additional analog channels at a rate of 200Hz, with GNSS satellite integration to aid the accuracy of inertial data. The analog channels can be used for measuring pilot stick force or control surface positions. The unit is USB-powered and easily installed, with a web-based interface for real-time data viewing and configuration. More information can be found on the BFS web site.

Aetherharp – MIDI Air Harp

We love alternative musical interfaces.  XenonJohn’s Aetherharp uses inexpensive Sharp GP2Y0A41SK0F analog distance sensors to determine hand proximity.

Like a theremin it is played without physical contact by the performer, but using light rather than antennas to determine proximity.  XenonJohn demonstrates the project on Instructables with his Teensy 3.5-powered Aetherharp.

Eight Sharp IR sensors are each configured to determine three discrete height levels, resulting in 24 possible notes.

Teensy’s USB MIDI capabilities are then leveraged to convert the hand gestures to sound via a connected laptop, which also provides power to the device.

Code and complete instructions can be found on Instructables, and a demonstration of the instrument can be seen below.

Open-Source Electronic Load

Electronic loads are important tools in the EE arsenal, useful for confirming that power supplies, batteries, and other power sources behave as expected. But their expensive prices motivated YouTuber EEforEveryone to create an open-source solution that relies on off-the-shelf PC components for cooling.

A custom Teensy 4.0-powered PCB takes the place of a PC motherboard, providing such facilities as coulomb counting and voltage and resistance measurement.

Up to four load modules can then be added, each using standard CPU cooling to a peak of around 275 watts. Source code can be found on GitHub, and a burn-in test can be enjoyed in the video below.

Digital Analog 2×1 Mixer

PJRC forums member rwalters wanted to build an analog mixer with digital control. The analog signal paths meant less expense, but without sacrificing digital convenience. The result is the PGA2310 2×1 Mixer Project.

Components are mostly socketed, so despite the name, a PGA2311 volume control could be auditioned instead, or alternate op-amps selected in place of the OPA2134. TT P260 panel pots and KIL OEJ knobs, combined with a laser-cut hardwood exterior provide a professional-looking finish. And of course, a Teensy 3.2 reads the potentiometers, sets volume output values, and does all the mixing maths. Source code, schematics, and more can be found in the project thread.

SATLLA-2B Nano-Satellite

We love seeing Teensy boards in use all over the place, from model rockets to jet-engine powered cars, but there’s something extra special about seeing them in space!

Imagine our joy when Ariel University’s Rony Ronen reached out to let us know that the Teensy 3.6 was being used as the main controller in their SATLLA-2B nanosatellite!

The 14×5×5cm sat transmits position and sensor data via amateur radio, which can be viewed on More detail can be found on the iFixit assembly guide, which provides a comprehensive overview of the DIY satellite and its construction.

Luma-1: An Enhanced LM-1 Drum Machine

The Human League, Yazoo, Gary Numan, Giorgio Moroder, Devo, Prince…Roger Linn’s LM-1 drum machine helped create the signature sound of a huge number of artists in the 80s.

After receiving an original LM-1 as a gift, Joe Britt (of Danger Research/T-Mobile Sidekick fame) decided to create his own enhanced version, based on the original TTL and Zilog Z80 design, but with a Teensy 4.1 coprocessor.

The original hardware design is enhanced with RAM-based samples instead of ROM, allowing the selection of different sounds. The original front panel switches are replaced with potentiometers that enable panning or pitch control. After countless hours of reverse engineering, Joe discovered that Roger Linn lived just five minutes away, and the two became fast friends as they geeked out on the neo-retro project together. The Luma-1 is a work in progress, with new features like an LCD screen, MIDI, and a new metal chassis appearing over time. Read more about on Roger Linn’s web site, and check out a demo in the video below!

Kenwood VS-2 Voice Synthesizer Emulator

Kosmo turned to the trusty Teensy 3.2 and Audio Adaptor to craft a replacement for the out-of-production Kenwood VS-2 Voice Synthesizer, commonly used in HAM radio.

The VS-2 is a voice module for the Kenwood TS-850, TS-690, TS-450 and other transceivers, which announces frequency and other settings upon request, making it of particular utility to blind operators. WAV files can be loaded from SD for complete customization.

Guild of Thieves Game Emulator

Thomas Dettbarn, also know and dettus on the PJRC forums, created a highly portable interpreter for the series of text adventures published by UK video game developer Magnetic Scrolls.

With versions running on Ubuntu, Debian, OpenBSD, macOS, Windows, and beyond, Thomas appears to have tested the the claim that it can run on “anything with a C compiler” and got it running on a Teensy 4.0.

The below shows the game being output to a PC terminal as ANSI art over the Teensy’s USB serial. Compiled firmware can be found in the forum thread, and a hex editor can be used to modify the command line parameters specified within the file, based on the interpreter’s instructions.

Lathe Digital Readout

John Knoll had added a set of iGaging DROs (Digital Read Outs) to his old manual lathe, but was starting to feel their limitations. They rely on coin cells and are too laggy for precision work.

Inspired by a video of a digital caliper being read by an Arduino, John went on to discover the Touch DRO project, which documented how to talk to several types of iGaging scales. This soon led to the creation of John’s own Teensy LC-based DIY DRO.

From spare parts, John soldered together a protoboard with two 7-segment 8-digit LED displays, two 4-character 14-segment displays, a shift register with 8 LEDs connected, a 4×6 button keypad for input, and a piezo buzzer for audio feedback. John then developed custom firmware and a nice enclosure, and is very pleased with the improvements over the prior budget system. Read more, plus find the source in the original forum thread.